Composite parts are known, which comprise a carrier, a decor layer and a foam layer, which lies between the carrier and the decor layer and connects the carrier and decor layer to one another.
Moreover, it is known to construct the decor layer in a multi-part manner of at least two skins which lie adjacent to one another. The problem with the manufacture of a component with a multi-part decor layer is the fact that during the back-foaming, foam may exit in the region of the separation line between the adjacent skins.
In order to prevent this, the patent JP 3347850 discloses a method, according to which, two skins with angled end sections are arranged on the surface of a tool, in a manner such that the angled end sections of the first and second skin are directed away from the surface of the tool. The end section of a skin comprises at least one sealing section in the form of a projection, which may engage into a corresponding opening or indentation of the oppositely lying end section of the other skin. Accordingly, the skins are connected to one another in a sealing manner. Thereafter, the skins are foamed to one another.
The disadvantage of this solution is the fact that in order to ensure an adequate sealedness, the sealing sections must be designed in a relatively complicated manner, that the skins must have a certain stiffness for maintaining their shape and that one must observe an exact arrangement of the skins.
An alternative embodiment type for preventing the foaming out between the skins is known from JP 2002052548. Thereby, the carrier comprises webs, which are designed just as high as the foam layer, which is introduced at a later point in time. The first skin is applied into the tool and subsequently the second skin, wherein the second skin with its end section overlaps the end section of the first skin. Subsequently, the carrier is arranged on the skins in a manner such that the webs come to lie precisely on the overlapping regions of the first and second skin. The skins and the carrier are subsequently back-foamed.
The disadvantage of such a solution is the fact that the carrier must be designed in a very complicated manner, which renders the production of the composite part more expensive and more complicated.
A third idea is known from JP 5-4236. Hereby, the first and the second skin in each case comprise two angled end sections, which are arranged lying on one another and are subsequently sewn to one another. This possibility also prevents foam from exiting out of the course of the border between the two skins lying on one another, during the back-foaming. Moreover, a frictional fit connection between the first and the second skin is created independently of the introduced foam.
The disadvantage of the solution which is shown there, is the fact that the sewing requires great effort and thus entails a high expense with regard to cost and time.
A further method is known from EP 1 278 339 A1. In order to prevent the exit of foam, an end section of the first skin has a negative shape and an end section of the second skin has a positive shape which corresponds to the negative shape and which is introduced mechanically into the negative shape in a working step before the back-foaming. Subsequently, the skins which are mechanically joined in such a manner are back-foamed in a back-foaming tool, wherein the foam may also penetrate in a gap remaining between the negative shape and the introduced positive shape and collapses there. The mechanical joining connection is reinforced by way of this.
The disadvantage of that solution is the multitude of working steps in different tools, which are to be carried out.